Cleaning chat history based on relevancy

ABSTRACT

A method is provided for deleting a content element of a chat history lacking long-term relevance. The method includes receiving a content element, conditionally assigning the content element to the topic, determining a relationship index value for the content element to the topic using a validity value, which is a function of an access rate and a credibility index value. The method may also include comparing the relationship index threshold value for the topic of a first chat user, where the content element has been generated by a second chat user. The method also includes linking the content element of the second chat user to the topic in the chat history of the first user, and deleting the content element if it is not linked to any other chat history of another chat user of the plurality of chat users.

BACKGROUND

The invention relates generally to a method, system and computer programproduct for deleting a content element of a chat history, and morespecifically, to keeping the content element or deleting the elementbased on its relevancy.

The increasing need to receive information quickly and easily hascontributed to an increasing use of chat systems during the work day.Today, chats are a common way to communicate with colleagues, either toget information an employee requires to perform a certain task, or—onthe other side—to break up the monotony of the day with short jokes ortopics relating to everyday life. In some work environments, chats havenot only enhanced communication by email but in many cases replaced partof the email traffic. Additionally, the chat communication channel is anadditional “back channel” in case of telephone conferences.

Typically, chat message exchanges are meant for the actual moment of achat message. However, often, there is a need to go back and search thehistory of a chat for certain information exchanged at an earlier time.Typically, such information is buried under longer chat messageexchanges, which may include also off-topic messages or messagesoverlapping with other message topics. There are cases in which the chathistory may be saved for a period of time, after which the chatcontributions are lost if a user has not saved content in another filefor longer term storage.

Storing chat contributions over an unlimited or undefined time mayrequire too much storage space at the chat system server and/or a localdevice. Also, because of the irrelevant private, everyday life chatcontributions, a lot of storage space may be consumed to only save somelonger term relevant information which may have a longer term businessvalue for one or more users.

SUMMARY

In one or more aspects, a computer-implemented method is provided fordeleting a content element of a chat history of a chat user of aplurality of chat users where the content element lacks a long-termrelevance. The computer-implemented method includes receiving a topicand a user-specified tag relating to the topic, receiving a contentelement of the chat user and storing the content element in a commonchat history repository, and assigning, by a semantic engine, thecontent element to the topic based on the tag being found in the contentelement. In addition, the computer-implemented includes determining arelationship index value for the content element to the topic using avalidity value for the content element. The validity value is a functionof an access rate to the topic and a credibility index value of anauthor of the content element. The method also includes comparing thedetermined relationship index value of the content element to arelationship index threshold value for the topic of a first chat user ofthe plurality of chat users, where the content element has beengenerated by a second chat user of the plurality of chat users. Further,the method includes linking the content element of the second chat userto the topic in the chat history of the first chat user, and deletingthe content element where it is not linked to any other chat history ofanother chat user of the plurality of chat users.

Systems and computer program products relating to one or more aspectsdisclosed herein may also be described and claimed herein.

Additional features and advantages may be realized through thetechniques described herein. Other embodiments and aspects are describedin detail herein, and are considered a part of the claimed aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

It should be noted that embodiments of the invention are describedherein with reference to different subject-matters. In particular, someembodiments are described with reference to method type claims, whereasother embodiments are described with reference to apparatus type claims.However, a person skilled in the art will gather from descriptionprovided that, unless otherwise notified, in addition to any combinationof features belonging to one type of subject-matter, also anycombination between features relating to different subject-matters, inparticular, between features of the method type claims, and features ofthe system type claims, is considered as to be disclosed within thisdocument.

The aspects defined above and further aspects of the present inventionare apparent from the examples of embodiments described herein, andexplained with reference to the examples of embodiments, but to whichthe invention is not limited. Embodiments of the invention aredescribed, by way of example only, with reference to the drawings, inwhich:

FIG. 1 shows a block diagram of one embodiment of a process for deletinga content element of a chat history, in accordance with one or moreaspects of the present invention;

FIG. 2 shows a block diagram of a more detailed process embodiment, inaccordance with one or more aspects of the present invention;

FIG. 3 shows a block diagram of one embodiment of a system for deletinga content element of a chat history, in accordance with one or moreaspects of the present invention; and

FIG. 4 shows an embodiment of a computing system including a system fordeleting a content element of a chat history, in accordance with one ormore aspects of the present invention.

DETAILED DESCRIPTION

In the context of this description, the following conventions, termsand/or expressions may be used.

The term ‘chat system’ or chat message communication system may denote asystem for enabling an online chat, and may thus refer to any kind ofcommunication over the Internet that offers a real-time transmission oftext messages from a sending user system to a receiving user system.Chat messages may generally be short in order to enable otherparticipants to grasp the content and respond quickly. Thereby afeeling, similar to a spoken conversation, is created whichdistinguishes chatting from other text-based online communication formssuch as Internet forums and email. Online chats may addresspoint-to-point communications as well as multicast communications fromone sender to many receivers.

Online chat, in a less stringent definition, may here primarily be anydirect text-based, one-on-one chat or one-to-many group chat (formallyalso known as synchronous conferencing), using tools such as instantmessengers, Internet Relay Chat (IRC) and talkers. The expression‘online chat’ comes from the word chat which means “informalconversation”. Online chat includes web-based applications that allowcommunication—often directly addressed, but anonymous between users in amulti-user environment.

The chat systems discussed in the context of this document may mainly berelated to one organization, i.e., one enterprise, or in an enterprisetogether with suppliers and customers, i.e., an ecosystem of anenterprise. Generally speaking, the chat users of the chat system inquestion may have some sort of common interest or organizationboundaries, i.e., a preselected group of chat users. Typically, this isnot the case for public chat systems which may not have any boundariesin terms of participants, i.e., chat users.

The term ‘a content element’ may denote a message or chat contributionin a chat system context. The content element includes typically acouple of words (could be only one word) up to several complete orincomplete sentences. Any text is possible, including program codesegments and/or Internet links and and/or acronyms and/or a sentencefragment and the like.

The term ‘long-term relevance’ may denote an importance of a contentelement to the chat community. The relevance may reflect anorganizational, content or business value for a specific group of chatusers. The relevance may be determined based on rules, policies and/ordedicated logical and/or mathematically definable dependencies. Thefollowing example may illustrate this: a discussion about the actualweather may be completely irrelevant for a semiconductor manufacturer;on the other hand, such a weather discussion may be of importance for abeverage company if it is to be decided how many beverage containersshould be ordered before the next weekend because it is of criticalimportance to order and/or deliver enough beverage containers and beable to fulfill the upcoming demand in the light of long, sunny hours onthe weekend.

The term ‘topic’ may denote an expression—i.e., one or a fewwords—describing themes relevant for the related chat user group. Thetopic may further be described in detail by one or a set of tags relatedto the topic. In the context of this document, the tag or the tags maybe user specific. Thus, a specific topic may be relevant for a chat userfor different reasons, under different aspects and thus, being describedwith individual tags.

The term ‘common chat history repository’ may denote a storageaccessible by the chat system for storing chat system relevant data likecontent elements of chat threads, administrative data, user specificdata—i.e., profiles, access information, etc.—as well as topics andtags, as defined above. All user specific data may be summarized in achat user profile. All non-chat-user specific data may be stored asadministrative data of the chat system. The common chat historyrepository may have the form of a database or content management system.In specific embodiments, the common chat history repository may beorganized in a wiki structure or a BLOG structure. A skilled person mayunderstand a BLOG (a truncation of the expression ‘weblog’) as adiscussion or informational website published on the World Wide Web—herebetter an Intranet or a closed user group in an Internet chatsystem—consisting of discrete, often informal diary-style text entries(known as “posts”).

The term ‘semantic engine’ may denote a technology for text processingfor analyzing a text or text segments, like content elements of chatcontributions. The semantic engine may relate a content element to atopic using the topic-related tags as well as its semantic meaning. Avery simple approach may be just to search for one or more of thedefinable tags per topic in the chat system in the content element. Amore sophisticated approach would also include synonyms or synonymphrases having the same or semantically similar meaning for such ananalysis. Basically, the semantic engine may tokenize the incomingcontent elements in order to relate them to the available topics. It mayalso be noted that a threshold value may be set for the semantic engineon order to define the similarity of expressions.

The term ‘relationship index value’ may denote a numerical value forrelationship of a content element from a chat user to a topic and at thesame time any user of the chat system.

The term ‘access rate to the topic’ may denote the number of accesses,requests or retrievals to a content item relating to a specific topic.The number may, e.g., be increased each time, a chat user accesses a(historic) content element relating to the topic or if a query regardinga specific topic may be received by the chat system.

The term ‘credibility index value’ may denote an expression of trustregarding a specific chat user, i.e., the credibility of the user. Thismay be measured in ‘likes’ a user may receive for past chatcontributions, i.e., historic content elements of the user, to a topic.Thus, the credibility index of a user may be topic dependent.

It may also be noted that, for comprehensibility reasons, termstypically relating to a coefficient having a value may be expressed bythe coefficient directly. E.g., the terms ‘tag’ and ‘tag value’ or‘topic’ and ‘topic value’ may be understood as equivalent. In a moremathematical oriented understanding the term topic may relate to thevariable named “topic” which may have a specific value like “October”,“street”, “semiconductor”, “gardening”, “rocket”, “robot” or “IBM”, justto name a couple of examples.

The proposed method for deleting a content element of a chat history mayoffer multiple advantages and technical effects:

For instance, significant of long-term chat storage space may be savedby not storing chat contributions which may have no long-term relevancy.Examples may be private chat contributions relating to the actualweather or cinema program if that is not part of the businessenvironment for the users exchanging chat messages.

The users—i.e., the employees of an enterprise or another close usergroup—may define the topics that are relevant for a specific businessenvironment. Tags may be used by the users—or machine-supported—todefine meaning of a topic. Thus, topics get a certain fingerprint basedon a unique combination of tags assigned to them. The meaning of a topicmay develop over time if the number of tags per topic grows over time.This way, sub-topics of a main topic may be definable. Additionally, themeaning of a topic may also be user-specific because each chat user maydefine his own tag cloud around a system-wide topic.

Categorizing chat contributions, i.e., content elements—automatically byanalyzing those using the known tags, may allow relating of certain chatcontributions to predefined topics. In case a topic is not clearlyidentifiable, a user may be asked to categorize the content element toone of the available topics in the system or define a new one. That way,a process as disclosed herein, and related system, may auto-learn newcontent and determination criteria in order to categorize chatcontributions. This may, e.g., be achieved by defining new tags fortopics and thus fine-tune meanings of a topic. Additionally, a semanticengine may also analyze the environment of a certain chatcontribution—i.e., the chat contributions/content elements before andafter the chat contribution in question in order to find a correct fitof a content element to a topic.

Using a relevancy factor, a relationship index and a reliability valueof a content element based on a series of different influential factors,the method may determine which content elements may be stored for alonger time—which may be definable—or to delete the chat contribution inquestion right away or after a predefined period of time. That way, onlythose chat contributions may be stored longer term that have a certainbusiness relevance for an enterprise or for a certain user community.Clearly, the proposed concept may not only work inside anenterprise—i.e., company internal chat systems—but also thosecommunities being stabled for a certain more or less precisely definedcontext (e.g., fisher's chat, motor-cycling chat, dancing chat, footballchat, etc.). Thus, chat contributions may be deleted which may beoff-topic for a certain context.

In summary, a collective memory based on chat contributions may begenerated over time. The self-learning capabilities—by means of addingrelevant topics and managing the topic portfolio, by means of adaptivelyexpanding tag clouds around topics and by automatically adjustingrelevancy values, validity values, relationship values and relatedthreshold values—contribute to a knowledge-base of an enterprise orcommunity that adapts itself over time with changing priorities andfocus areas. The so developing knowledge basis may also be seen asdigital experience or digital memory of an enterprise and may help newmembers of the enterprise and/or community to identify views,evaluations and evolutions of earlier discussed topics.

Furthermore, by means of limiting the amount of chat contribution—i.e.,chat elements—it becomes easier for a user to search the history for aspecific information. He may simply find the content it is looking forfaster.

In the following discussion, additional embodiments of the method andthe related system will be described.

The initially noted needs may be addressed by a method for deleting acontent element of a chat history, a system for deleting a contentelement of a chat history, a computing system, and a computer programproduct, according to the claims presented.

According to one aspect of the present invention, a method for deletinga content element of a chat history may be provided. The chat historymay be related to a chat user of a plurality of chat users and thecontent item may be deleted if it does not have a long-term relevance.The method may include receiving a topic and a user specific tagrelating to the topic, receiving a content element—i.e., a chatcontribution—of the chat user and store it in a common chat historyrepository of, e.g., a chat system server.

The method may further include assigning, by a semantic engine, thecontent element to the topic if the tag is found in the content element,determining a relationship index value for the content element to thetopic using a validity value for the content element. The validity valuemay be a function of an access rate to the topic and a credibility indexvalue of the chat user author of the content element.

Furthermore, the method includes comparing the determined relationshipindex value of the content element to a relationship index thresholdvalue for the topic of a first chat user of the plurality of chat users,wherein the content element has been generated by a second chat user ofthe plurality of chat users, linking the content element of the secondchat user to the topic in the chat history of the first user, anddeleting the content element if it is not linked to any other chathistory of another chat user of the plurality of chat users.

According to another aspect of the present invention, a system fordeleting a content element of a chat history may be provided. The systemmay have specific modules and units adapted to performing the method fordeleting a content element of a chat history.

Furthermore, embodiments may take the form of a related computer programproduct, accessible from a computer-usable or computer-readable mediumproviding program code for use, by or in connection with a computer orany instruction execution system. For the purpose of this description, acomputer-usable or computer-readable medium may be any apparatus thatmay contain means for storing, communicating, propagating ortransporting the program for use, by or in a connection with theinstruction execution system, apparatus, or device.

One embodiment of the method may also include using the topic as sortingcriterion in the common chat history repository, and publishing thecontent elements sorted by the topic. Hence, this process may beinstrumental in developing, maintaining and making accessible acollective digital memory of a group or company, i.e., of all thoseusing the chat system.

According to an advantageous embodiment of the method, the assigning,the determining, the comparing, the linking and the deleting may each beperformed periodically or at a predefined point in time. There may be aseries of predefined times defined and potentially adapted a pluralityof points in time. Thus, a consolidation of the common chat historyrepository may be performed regularly. This may also enable to reflectchat elements with a later time stamp than that of a chat element underthe same thread analysis before a deletion.

According to one embodiment of the method, the validity index may bedefined as:validity index=access rate to the topic*credibility index value,wherein the credibility index value of a chat user is defined as anumber of positive feedback tags—e.g., ‘likes’, ‘thumb up messages’ orsimilar—related to content elements of the chat user for a specifictopic, i.e., theme. Thus, not every content element will be archived forthe future but only those content elements have a chance to be storedlonger term having at least a certain level of validity. The access rateto the topic may be understood as the access rate by all potentialusers, and not limited to a specific chat user. The access rate to thetopic may—in general—reflect the interest of the chat community to thetopic.

According to a further embodiment of the method, the relationship indexmay be defined by:max[(#tag_user-i/#tag_current)/validity index], for all i userssubscribed to a specific topic;wherein

#tag_user-i is a number of tags defined for a topic by user-i; and

#tag_current is a number of tags present in the content element.

Here, the expression ‘present’ may also include synonyms and/orsemantically equal and or similar expressions. The validity index ofcontent element has already been defined in the paragraph above.

Hence, the relationship index may determine to which topic a contentelement may be related to the most. This value may be checked userdependent because each chat user may (a) define his own tags for atopic, and (b) has its own number of tags for the topic. A simpleexample may illustrate the relationship: a content element includestag1, tag2, tag5 and tag6; and the user-1 has defined one of the topicsusing his tags tag1, tag3 tag6. Thus, in this example, #tag_user-1=4because chat user-1 has defined four tags for his understanding of therelevant topic. In the same example, the #tag_current is a number oftags present in the content element; thus, #tag_current=2, because tag1and tag6 are included in the content element.

According to an optional embodiment of the method, a user specificweight value may be assigned to the user specific tag of a topic. Moreparticularly, some tags may be more important than others, according tothe user, so their presence in a content element may have a higherweight, so #tag_current(i) is not simply the “counter” of the matchingtags, but the weighted matching tags, i.e., multiplied, with animportance coefficient which may be a decimal number between from0—meaning not relevant—to 1—having importance. In a further optionalembodiment defining a topic may be restricted to a subset of all chatusers—e.g., “key users” or administrators—considered as referencechampions.

According to one embodiment, the method may also include receiving aninput value—in particular from a chat user—for determining to whichtopic a newly received content element is to be assigned if a determinednumber of tags—potentially combined with weighing factors—in the contentelement does not indicate a unique relationship to exactly one topic.This may give the chat user influence on the functionality of thediscussed chat system. The chat user may be the final decision maker. Incase of uncertainty, the user may also decide to relate the newlyreceived—or better newly created—content element to the related twotopics.

According to a further embodiment of the method, the assigning, by thesemantic engine, the content element to the topic may also take intoaccount earlier and/or later content elements in a same chat thread.Hence, a content element to be analyzed and potentially be marked ashaving a longer-term relevance may be accessed in a near-term contextualenvironment of the content element, i.e., content elements before andafter the actual content elements from the chat user or those chatuser(s) having responded to the content element by another contentelement. Thus, this may make the complete method and system morecontext-sensitive and accurate.

A detailed description of the figures is provided below. Allinstructions in the figures are schematic. Firstly, a block diagram ofan embodiment of the inventive method for deleting a content element ofa chat history is given. Afterwards, further embodiments, as well asembodiments of the system for deleting a content element of a chathistory, are described.

FIG. 1 shows a block diagram of one embodiment of a method 100 fordeleting a content element of a chat history of a chat user of aplurality of chat users if the content element does not have a long-termrelevance, in accordance with one or more aspects of the presentinvention. The relevance may express an intrinsic interest of the usercommunity of the chat system to maintain a content element for a longerperiod of time than those content elements not being of generalinterest. The method 100 includes receiving, 102, a topic. The topic maybe a term being available globally within the chat system. Thus, everychat user may see it. On the other side, there may be at least one userspecific tag relating to the topic. Hence, every user may define a topicaccording to the user's own experience background, and with the user'sown words, e.g., his own tags.

The method includes receiving, 104, a content element of a chat user.Such a content element may be used synonymously for a chat contributionor simply a chat post within the chat system. Typically, a contentelement or chat contribution is directed to a conversation partner in achat thread. The content element may be stored in a common chat historyrepository, e.g., of the chat system server.

Furthermore, the method includes assigning, 106, the content element tothe topic if the tag is found in the content element. This is done by asemantic engine. In this sense, the expression “if the tech is found” isto be interpreted as “semantically found”. This process may also becharacterized as tokenizing the content element and try to find relatedexpressions—in the easiest case equal expressions—in the word cloudsbuilt by the tags around the topics by the chat users. If a tag matchexists between a newly received content element and more than one topic,the chat user having created the context element may be given the choiceto decide to which topic the content element should be related. In oneembodiment, the tag in question may be related to more than one topic ifa straightforward determination of a specific topic is not possible.

As a further step, the method includes determining, 108, a relationshipindex value for the content element to the topic, i.e., it may bedecided how close the content element is semantically linked to thetopic. For this, a validity value for the content element is used.

The validity value is a function—in particular a mathematical product—ofan access rate to the topic—and/or related content elements—and acredibility index value of the chat user—i.e., the author—of the contentelement.

Additionally, the method includes comparing, 110, the determinedrelationship index value of the content element to a relationship indexthreshold value for the topic of a first chat user of the plurality ofchat users, wherein the content element has been generated by a secondchat user of the plurality of chat users, linking, 112, the contentelement of the second chat user to the topic in the chat history of thefirst user, and deleting, 114, the content element if it is not linkedto any other chat history of another chat user of the plurality of chatusers.

As a result, a consolidated chat history remains in a common chatrepository representing a community knowledge of the chat users andpreserve it for future access by any chat user of the community, even ifthe chat user may not have been part of the original discussion.

FIG. 2 shows a block diagram of one embodiment of a more detailed flowchart 200, in accordance with one or more aspects of the presentinvention. After the start 202 of the procedure, a new chat entry may beparsed, 204. It may be understood that the procedure repeats itselfuntil all untreated—non-parsed chat entries—may have been parsed, and adecision about a deletion may have been made. Next, the new chat entrymay be matched, 206, against user and system parameters (as discussedabove), 208. If no match is found—case “no”, the local and global chatcontent is cleaned up, 222, i.e., assessed to have no long-termrelevance, and deleted. Then, the procedure ends, 224, or—if otheruntreated content elements exist—restarts.

In case of a found match—case “yes”—the topic is extracted, 210, and areliability validity index is determined, 212. If the reliability indexis below or equal to a related threshold value, 214, the local chathistory will be cleaned up, 222, as explained above. The reliabilityindex can also be interpreted as the validity index.

In case the reliability index is above the related threshold value, therelevant information is extracted, 216, from the content element, thecommon chat history is updated, 218, a notification may optionally besent to the subscribers (notify, 220), and the local chat history may becleaned up, 222. Then, the procedure ends or restarts, as discussedabove.

FIG. 3 shows a block diagram of an embodiment of the system 300 fordeleting a content element of a chat history of a chat user of aplurality of chat users if the content element does not have a long-termrelevance. The system 300 includes a receiver unit 302 adapted forreceiving a topic and a user chat specific tag relating to the topic,and a collection unit 304 adapted for receiving content elements of thechat users. The collection unit is also adapted for storing the contentelements in a common chat history repository.

The system 300 also includes an analysis module 306 adapted foranalyzing the content element by a semantic engine adapted for assigningthe content element to the topic, if the semantic engine determines thatthe content element relates to the tag, and a determination unit 308adapted for determining a relationship index value for the contentelement to the topic using a validity value for the content element. Thevalidity value is a function of an access rate to the topic and acredibility index value of an author of the content element.

Additionally, the system 300 includes a comparing unit 310 adapted forcomparing the determined relationship index value of the content elementto a relationship index threshold value for the topic of a first chatuser of the plurality of chat users, wherein the content element hasbeen generated by a second chat user of the plurality of chat users, alinking module 312 adapted for linking the content element of the secondchat user to the topic in the chat history of the first chat user, and adeletion module 314 adapted for deleting the content element if it isnot linked to any other chat history of another chat user of theplurality of chat users.

Embodiments of the invention may be implemented together with virtuallyany type of computer, regardless of the platform being suitable forstoring and/or executing program code. FIG. 4 shows, as an example, acomputing system 400 suitable for executing program code related to theproposed method.

The computing system 400 is only one example of a suitable computersystem and is not intended to suggest any limitation as to the scope ofuse or functionality of embodiments of the invention described herein.Regardless, computer system 400 is capable of being implemented and/orperforming any of the functionality set forth hereinabove. In thecomputer system 400, there are components, which are operational withnumerous other general purpose or special purpose computing systemenvironments or configurations. Examples of well-known computingsystems, environments, and/or configurations that may be suitable foruse with computer system/server 400 include, but are not limited to,personal computer systems, server computer systems, thin clients, thickclients, hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, set top boxes, programmable consumerelectronics, network PCs, minicomputer systems, mainframe computersystems, and distributed cloud computing environments that include anyof the above systems or devices, and the like. Computer system/server400 may be described in the general context of computersystem-executable instructions, such as program modules, being executedby a computer system 400. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 400 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in the figure, computer system/server 400 is shown in the formof a general-purpose computing device. The components of computersystem/server 400 may include, but are not limited to, one or moreprocessors or processing units 402, a system memory 404, and a bus 406that couples various system components including system memory 404 tothe processor 402. Bus 406 represents one or more of any of severaltypes of bus structures, including a memory bus or memory controller, aperipheral bus, an accelerated graphics port, and a processor or localbus using any of a variety of bus architectures. By way of example, andnot limitation, such architectures include Industry StandardArchitecture (ISA) bus, Micro Channel Architecture (MCA) bus, EnhancedISA (EISA) bus, Video Electronics Standards Association (VESA) localbus, and Peripheral Component Interconnects (PCI) bus. Computersystem/server 400 typically includes a variety of computer systemreadable media. Such media may be any available media that is accessibleby computer system/server 400, and it includes both, volatile andnon-volatile media, removable and non-removable media.

The system memory 404 may include computer system readable media in theform of volatile memory, such as random access memory (RAM) 408 and/orcache memory 410. Computer system/server 400 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 412 may be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a ‘hard drive’). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a ‘floppy disk’), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media may be provided.In such instances, each can be connected to bus 406 by one or more datamedia interfaces. As will be further depicted and described below,memory 404 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

The program/utility, having a set (at least one) of program modules 416,may be stored in memory 404 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 416 generally carry out the functionsand/or methodologies of embodiments of the invention as describedherein.

The computer system/server 400 may also communicate with one or moreexternal devices 418 such as a keyboard, a pointing device, a display420, etc.; one or more devices that enable a user to interact withcomputer system/server 400; and/or any devices (e.g., network card,modem, etc.) that enable computer system/server 400 to communicate withone or more other computing devices. Such communication can occur viaInput/Output (I/O) interfaces 414. Still yet, computer system/server 400may communicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 422. As depicted, network adapter 422may communicate with the other components of computer system/server 400via bus 406. It should be understood that although not shown, otherhardware and/or software components could be used in conjunction withcomputer system/server 400. Examples, include, but are not limited to:microcode, device drivers, redundant processing units, external diskdrive arrays, RAID systems, tape drives, and data archival storagesystems, etc.

Additionally, system 300 for deleting a content element of a chathistory may be attached to the bus system 406.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinaryskills in the art without departing from the scope and spirit of thedescribed embodiments. The terminology used herein was chosen to bestexplain the principles of the embodiments, the practical application ortechnical improvement over technologies found in the marketplace, or toenable others of ordinary skills in the art to understand theembodiments disclosed herein.

The present invention may be embodied as a system, a method, and/or acomputer program product. The computer program product may include acomputer readable storage medium (or media) having computer readableprogram instructions thereon for causing a processor to carry outaspects of the present invention.

The medium may be an electronic, magnetic, optical, electromagnetic,infrared or a semi-conductor system for a propagation medium. Examplesof a computer-readable medium may include a semi-conductor or solidstate memory, magnetic tape, a removable computer diskette, a randomaccess memory (RAM), a read-only memory (ROM), a rigid magnetic disk andan optical disk. Current examples of optical disks include compactdisk-read only memory (CD-ROM), compact disk-read/write (CD-R/W), DVDand Blu-Ray-Disk.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including anobject-oriented programming language such as Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus', and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus', or anotherdevice to cause a series of operational steps to be performed on thecomputer, other programmable apparatus or other device to produce acomputer implemented process, such that the instructions which executeon the computer, other programmable apparatus', or another deviceimplement the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The flowcharts and/or block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or act or carry out combinations of special purpose hardwareand computer instructions.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the invention. As usedherein, the singular forms “a”, “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will further be understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or steps plus function elements in the claims below are intendedto include any structure, material, or act for performing the functionin combination with other claimed elements, as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skills in the artwithout departing from the scope and spirit of the invention. Theembodiments are chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skills in the art to understand the invention forvarious embodiments with various modifications, as are suited to theparticular use contemplated.

What is claimed is:
 1. A computer-implemented method of facilitatingprocessing within an online chat system by saving long-term storagespace of a common chat history repository of the online chat system,said computer-implemented method comprising: ascertaining, by the onlinechat system, whether a content element of the common chat historyrepository should be deleted, the common chat history repositorycomprising a database of online text-based communications, theascertaining based on said content element lacking a long-termrelevance, the ascertaining comprising: receiving a topic and a userspecific tag relating to said topic; receiving said content element of achat user of a plurality of chat users and storing the content elementin the common chat history repository; assigning, by a semantic engine,said content element to said topic based on said tag being found in saidcontent element; determining a relationship index value for said contentelement to said topic using a validity value for said content element,said validity value being a function of an access rate to said topic anda credibility index value of an author of said content element;comparing said determined relationship index value of said contentelement to a relationship index threshold value for said topic of afirst chat user of said plurality of chat users, wherein said contentelement has been generated by a second chat user of said plurality ofchat users; linking said content element of said second chat user tosaid topic in said chat history of said first chat user; and based onthe ascertaining, deleting, by the online chat system, said contentelement where it is not linked to any other chat history of another chatuser of said plurality of chat users, the deleting saving the long-termchat storage space.
 2. The computer-implemented method according toclaim 1, further comprising: using said topic as sorting criterion insaid common chat history repository; and publishing said contentelements sorted by said topic.
 3. The computer-implemented methodaccording to claim 1, wherein said assigning, said determining, saidcomparing, said linking and said deleting are each performedperiodically or at a predefined point in time.
 4. Thecomputer-implemented method according to claim 1, where said validityvalue is defined as:validity index=access rate to said topic*credibility index value,wherein said credibility index of a chat user is a number of positivefeedback tags related to content elements of said chat user.
 5. Thecomputer-implemented method according to claim 4, wherein saidrelationship index is defined by:max[(#tag_user-i)/#tag_current)/validity of content element], for all iusers, wherein: #tag_user-i is a number of tags defined for a topic ofuser-i subscribed to a specific topic; and #tag_current is a number oftags present in said content element.
 6. The computer-implemented methodaccording to claim 1, wherein user specific weight values may beassigned to said user specific tags of a topic.
 7. Thecomputer-implemented method according to claim 1, further comprising:receiving an input value for determining to which topic a newly receivedcontent element is to be assigned based on a determined number of tagsin said content element not indicating a unique relationship to exactlyone topic.
 8. The computer-implemented method according to claim 1,wherein said assigning, by said semantic engine, said content element tosaid topic also takes into account at least one of earlier or latercontent elements in a same chat thread.
 9. A system for facilitatingprocessing within an online chat system by saving long-term storagespace of a common chat history repository of the online chat system,said computer system comprising: a memory; and a processor incommunications with the memory, wherein the system performs a methodcomprising: ascertaining, by the online chat system, whether a contentelement of the common chat history repository should be deleted, thecommon chat history repository comprising a database of onlinetext-based communications, the ascertaining based on said contentelement lacking a long-term relevance, the ascertaining comprising:receiving a topic and a user specific tag relating to said topic;receiving said content element of a chat user of a plurality of chatusers and storing the content element in the common chat historyrepository; assigning, by a semantic engine, said content element tosaid topic based on said tag being found in said content element;determining a relationship index value for said content element to saidtopic using a validity value for said content element, said validityvalue being a function of an access rate to said topic and a credibilityindex value of an author of said content element; comparing saiddetermined relationship index value of said content element to arelationship index threshold value for said topic of a first chat userof said plurality of chat users, wherein said content element has beengenerated by a second chat user of said plurality of chat users; linkingsaid content element of said second chat user to said topic in said chathistory of said first chat user; and based on the ascertaining,deleting, by the online chat system, said content element where it isnot linked to any other chat history of another chat user of saidplurality of chat users, the deleting saving the long-term chat storagespace.
 10. The system according to claim 9, further comprising: usingsaid topic as sorting criterion in said common chat history; andpublishing said content elements sorted by said topic.
 11. The systemaccording to claim 9, wherein said assigning, said determining, saidcomparing, said linking and said deleting are each performedperiodically or at a predefined point in time.
 12. The system accordingto claim 9, wherein said validity value is defined as:validity index=access rate to said topic credibility index value, wheresaid credibility index of a chat user is a number of positive feedbacktags related to content elements of said chat user.
 13. The systemaccording to claim 12, wherein said relationship index is defined by:max[(#tag_user-i)/(#tag_current)/validity index] for all i userssubscribed to a specific topic, and wherein: #tag_user-i is a number oftags defined for said topic by user-i; and #tag_current is a number oftags present in said content element.
 14. The system according to claim9, wherein user specific weight values may be assigned to said userspecific tags of a topic.
 15. The system according to claim 9, furthercomprising: receiving input by a chat user for determining to whichtopic a newly received content element is to be assigned based on adetermined number of tags in said content element not indicating aunique relationship to exactly one topic.
 16. The system according toclaim 9, wherein said assigning, by said semantic engine, said contentelement to said topic also takes into account at least one of earlier orlater content elements in a same chat thread.
 17. A computer programproduct for facilitating processing within an online chat system bysaving long-term storage space of a common chat history repository ofthe online chat system, said computer program product comprising: anon-transitory computer readable storage medium having programinstructions embodied therewith, said program instructions beingexecutable by one or more computing systems to cause said one or morecomputing systems to perform a method comprising: ascertaining, by theonline chat system, whether a content element of the common chat historyrepository should be deleted, the common chat history repositorycomprising a database of online text-based communications, theascertaining based on said content element lacking a long-termrelevance, the ascertaining comprising: receiving a topic and a userspecific tag relating to said topic; receiving said content element of achat user of a plurality of chat users and store the content element inthe common chat history repository; assigning, by a semantic engine,said content element to said topic based on said tag being found in saidcontent element; determining a relationship index value for said contentelement to said topic using a validity value for said content element,said validity value being a function of an access rate to said topic anda credibility index value of an author of said content element;comparing said determined relationship index value of said contentelement to a relationship index threshold value for said topic of afirst chat user of said plurality of chat users, wherein said contentelement has been generated by a second chat user of said plurality ofchat users; linking said content element of said second chat user tosaid topic in said chat history of said first chat user; and based onthe ascertaining, deleting, by the online chat system, said contentelement where it is not linked to any other chat history of another chatuser of said plurality of chat users, the deleting saving the long-termchat storage space.
 18. The computer program product of claim 17,wherein the program instructions are executable by the one or morecomputing systems to cause the one or more computing systems to: usesaid topic as sorting criterion in said common chat history repository;and publish said content elements sorted by said topic.
 19. The computerprogram product of claim 17, wherein said assigning, said determining,said comparing, said linking and said deleting are each performedperiodically or at a predefined point in time.
 20. The computer programproduct of claim 17, where said validity value is defined as:validity index=access rate to said topic*credibility index value,wherein said credibility index of a chat user is a number of positivefeedback tags related to content elements of said chat user.